Allen's Quandary

Allen was in the process of sprucing up his large backyard by planting trees, when he came to a tough decision. He had already planted the following types of trees: Khejri, Himalayan Pine, Maple, Llala Palm, and Agave Cactus, when he noticed that he could only plant one more. Given the trees that he had already planted, which of the following type would he choose?